Author Topic: 20 x 30 1 1/2 story with sunroom and basement  (Read 89767 times)

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Offline GreenPointGuy

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20 x 30 1 1/2 story with sunroom and basement
« on: July 28, 2007, 09:32:33 AM »
Greetings,
Below are three pics (if the links work properly) of my preliminary attempt
at modifications to the 20' x 30 x 1 1/2 story. I would appreciate any thoughts
or concerns any of you might have regarding the layout and structure. House location will be
NW Michigan (lower peninsula).
1) I'd like to go with 12' walls if possible but also retain the 'great room' concept.
    I would have the loft rafters showing through the cut outs.
2) Not yet sure how to do the stairs to go from the loft to the basement.
    I love firepoles .. but they are unidirectional!
3) Not sure about supporting the sunroom. Maybe with steel I-beams (or equivalent)?
    or having a 'bump-out' in the basement.
4) The slab/basement will be built on ground level and the back-filled on 3 sides.
    Any loading concerns here?
5) If anyone has any tips on how to create the sunroom roof in Better Homes & Gardens V6
    and also the cutouts in the floor ... please advise. (or have a retractable sunroof as shown .. just kidding!)





« Last Edit: July 28, 2007, 09:41:52 AM by GreenPointGuy »

Offline glenn kangiser

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #1 on: July 28, 2007, 09:29:00 PM »
Didn't check the fine points but overall -- I like it. :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

Offline John Raabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #2 on: August 01, 2007, 06:47:02 AM »
Nice job on the model. :D

For the sunroom I would do a simple shed roof bearing on the big gable rafters. You can put tempered glass skylights into this roof if you like. Those details can be downloaded here if you have a PlanHelp subscription. The loading on the sunroom posts is not dramatic. A wooden header (shown in the plans) will be fine. The other end of the sunroom rafters can put their load on the common wall.

Here is an L-shaped stair plan that would work well for the 1-1/2 story with a basement, but it is bigger than the cottage stair in the plan and will need some modification to the floorplan.

The basement plan can be derived from the crawlspace plan that comes in the 1-1/2 story plan set. Your designer will need to add the sunroom footprint and step the concrete walls down to meet your grade requirements. This will still be the 8" foundation wall shown in your plans but will have more reinforcement and a frame wall on the daylight side with the window and door.
« Last Edit: August 01, 2007, 07:28:18 AM by jraabe »
None of us are as smart as all of us.

Offline GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #3 on: August 01, 2007, 11:49:21 AM »
Gents, Thx Much for your comments/suggestions.
I am a member of Planhelp.com so I'll dig around in there for more goodies.
Below is a possible variation on the sunroom theme.
I would still retain the original 20x30x1 1/2 form but add the sunroom
under an extended roof. The sunroom volume could then perhaps connect
to the knee wall above and vent via internal windows to allow a 'cylindrical' flow
path through the basement (with some type of low velocity fan-assisted venting in the first floor).
Does anyone see any issues .. structural and/or thermal?
--> Jim


Offline John Raabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #4 on: August 01, 2007, 01:44:51 PM »
Cool!

Variations (improvements) on an envelope house solar design
None of us are as smart as all of us.

Offline GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #5 on: August 15, 2007, 07:22:13 AM »
Well, I have let go of the single plane roof line geometry for the house/sunroom roof
and am back to the sunroom being attached with a shed roof style. I am still going for the semi-envelope
solar concept.
My question is:
Is there an optimum height location (for structural integrity and/or ease of construction) for the 'joint' of the sunroom roof?
In the picture below I am showing 3 height locations represented by different colors.
Thx --> Jim

(ps: Google SketchUp is pretty handy for creating exteriors)


Offline John Raabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #6 on: August 15, 2007, 07:43:55 AM »
Any of those three options could work. I think the "over the wall" middle option is likely to be the easier one to build. There the rafters just overlap and the ventilation over the insulation is continuous as is the roofing.

Nice to see your work with SketchUp! That's a powerful little program.
« Last Edit: August 15, 2007, 09:49:43 AM by jraabe »
None of us are as smart as all of us.

jstig

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #7 on: September 19, 2007, 11:36:59 AM »
Great house plan!
There is a site I found that sells a version of solar envelop houses called Enertia - the url is http://enertia.com/
It seems they use airflow thru the whole house from the south sunroom to the north wall envelop and the basement - maybe that concept provides a more even heat.  They sell kits - kinda  pricy and most of them too big for me - but I like the concept.  Has anyone seen this site and if so what is your opinion?
I guess I am asking the gurus here (like John, Glenn, and Peg) :)   I like the fact that u can leave the house unattended and unheated without any worries.

glenn-k

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #8 on: September 19, 2007, 12:00:57 PM »
Looks like some of the ideas could be incorporated into other designs.

jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #9 on: September 19, 2007, 12:52:47 PM »
It's a big topic. I've designed a number of envelope houses over the years. They can work pretty well (never as well as the promoters claim however). There are some safety problems in the classic design and they are not the most cost effective solution in most climates.

Like all solar houses these will work best in strong winter sun environments - not in cold northern weak sun areas.

From my experience, the most cost effective formula for balancing the three key ingredients of a natural energy house - south glass, insulation and thermal mass are the ones I have put in the Sunkit series of site evaluation and preliminary design tools.

SunKit Tools


jstig

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #10 on: September 19, 2007, 09:10:19 PM »
Thanks for the responses.   I guess the key is "cost effective" and what would work best for the particular site.   For a small house like I want to build - probably something the size of the builders cottage - a double envelop is probably overkill.  I intend to buy one of your sets of plans when I finally decide which one will be best for me and I will prob join your plans support site when I get into the serious planning and building phase.  My cabin site is in western Maryland.  It can get very cold there in winter since it is up on the Apalachian Plateau.  It is consistently 10 degrees or more cooler than the rest of Maryland and Spring is usually around 3 weeks later than here in Baltimore. This is a great forum with a lot of help and encouragement for us dreamers.  My dad built our family house when I was 12 with the help of my 4 brothers and myself - it was a great learning experience for me and I have been wanting to build my cabin for awhile.   My goal is to begin building next spring.

Thanks,
Jim

GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #11 on: September 20, 2007, 08:06:30 AM »
Greetings,
I am still working on my plans in prep. for submitting for the building permit and have a couple of questions about what is written in the 'Cathedral Ceilings Details' .pdf. It states:
'The details presented here can be used in the areas of the 20'
wide cottage house where you don't need a loft. This will give you a full cathedral ceiling over the living room (for instance) with
heavy timber-like beams tying the walls together every 4 feet.'
1) Does this imply that structurally, I should not have a cathedral ceiling running the full length of the cottage (ie: above the loft area)?
2) Is it possible to reduce the number of beams (every 4') by increasing the cross-section area of the beam? So that maybe one larger beam every 6' or even 8'?
---> JG

jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #12 on: September 20, 2007, 10:41:14 AM »
The Cathedral Ceiling Details in the booklet have a rafter tie that sits on top of the wall plates every 4'. This wouldn't give you much headroom in the loft assuming you are setting the loft floor on the ledger.  ;)

Now, there are other ways to do a full cathedral ceiling. The most common is to have a structural ridge beam and then the rafters can be nailed to it directly with no ties. This ridge beam will have to be sized locally to the snow and wind loads as well as the span length. You would want a post or two under this beam since it would be  huge if it were to span the length of the building. :-/

Collar or beam ties at every other rafter (48" o/c) is a well documented traditional framing practice that will not normally require engineering. If you go longer between ties this might also be fine but it will be more likely to require local engineering.

What I have tried to do with this house is design it for the simplest to build common practice framing techniques. These have wide acceptance in many jurisdictions. Some locallities, however, will require engineering on all submitted plans. If this is the case then you may want to work with your local engineer and explore other options than the ones I have shown.
« Last Edit: September 20, 2007, 10:49:29 AM by jraabe »

Micky

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #13 on: September 20, 2007, 03:12:49 PM »
I just saw this same discussion on another forum.  Maybe they will have some interesting input. http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=94837.1&maxT=1

For what it is worth, I did as John suggest with the ties every other rafter.  I did the full loft so my floor joist (48 OC) also work to tie the walls together.
« Last Edit: September 20, 2007, 03:22:30 PM by Micky »

jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #14 on: September 21, 2007, 06:28:39 AM »
In my 1-1/2 story design I do not put all of the rafter thrust onto the balloon framed walls. The site built trusses are essentially roof rafters with a higher than normal collar tie to allow for a reasonable ceiling. This triangulates the roof structure making it naturally more rigid.

The diagram the poster worked out with and got approved by his inspector is using the same idea.

GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #15 on: September 25, 2007, 06:46:19 AM »
Thank you for your thoughts John and Micky. I think I am starting to understand .. but I still have a question.
Below are borrowed photos from Micky's nice home and also AAA-Day's 20x34 in Michigan. In comparing the two pictures (see below) I see Micky's use of the 2x6 collar ties
and in AAA-Day's photo he shows the central roof beam with no collar ties. In AAA-Day's photo I don't see any support posts that John suggested.
Where ideally could this support(s) be located .. and ... should there be a secondary support in my basement directly under the upper one?
Thx Much --> Jim



jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #16 on: September 27, 2007, 10:31:57 AM »
When you design a structural roof beam you can span larger distances with deeper and wider beams. In a small house you could go with a big (expensive) glulam and probably go end to end. That may be what we are seeing in the photo - as that could be a 14" to 16" deep beam. Otherwise you can use smaller beams and post them all the way down to footers.

The size and support of this beam will depend on the local snow loads, roof spans, and other factors.

You need to have a local engineer design this as it will be very specific to the location and design of the project and is outside the scope of the stock plan you have now.
« Last Edit: September 27, 2007, 10:37:44 AM by jraabe »

GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #17 on: September 28, 2007, 08:44:53 AM »
Thank you John for the scoop.
Also, I have recently been thinking about adding a dormer for the light gathering benefits.
Somewhere in here I read that you were going to place
some documentation on creating a dormer for your designs into the PlanHelp.com site.
I searched there but didn't find anything (or perhaps I wasn't looking in the right place).
Do you have any suggestions/assistance?
Thx Much ---> Jim

jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #18 on: October 02, 2007, 12:54:56 PM »
Jim:

I will do an update on this this month and get it up on the planhelp site. It is a valuable option.
« Last Edit: October 02, 2007, 12:55:19 PM by jraabe »

jraabe

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #19 on: October 07, 2007, 03:09:30 PM »
I just added an alternative rafter framing system for the 20' wide 1-1/2 story plan and details for doing gable and shed dormers.

It can be downloaded from the planhelp (membership) site at the link below:

http://tinyurl.com/9jynf - Scroll down to the third plan in this section of the download library.



Note: with a little modification this system could also be used to frame the attic of the 2-story universal and turn it into living space. (You would need a dormer over the stair to continue it on up.)
« Last Edit: October 07, 2007, 03:17:52 PM by jraabe »

GreenPointGuy

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Re: 20 x 30 1 1/2 story with sunroom and basement
« Reply #20 on: October 08, 2007, 03:48:30 AM »
Thx Very Much !!
Very helpful information.
Highest Regards ---> Jim